Large numbers of people who have tested positive for Covid-19 have yet to receive a call confirming the diagnosis which would set in train efforts to trace their contacts.
The number of people due to be called over a positive test result has varied between 100 and more than 400 over the past 10 days, and on Monday stood at 250, according to sources, who said about 100 of those due to be called had been on the list for at least two days.
The HSE has yet to publish any data on the performance of contract tracing in terms of wait times or time taken to trace all contacts, but is said to be developing an appropriate metric.
The initial call that precedes the contract tracing process is made by a clinician, who provides medical advice to the person who has tested positive. Contact tracing cannot begin until this call is made.
The second call is made by a contact tracer – a non-clinician – who asks the person who has tested positive details of all their close contacts. While up to 100 people have at times been queued to be called in this part of the process, it is not subject to significant delays, according to people familiar with the process.
The third set of calls, made by non-clinicians working from a call centre, is made to the contacts of the confirmed case, who are asked to self-isolate whether they have symptoms or not, and to contact a GP if they have symptoms. Any delays here too are relatively minor.
Struggle to remember
Due to delays in the testing process over the past month, many confirmed cases had recovered – or, in some cases, been hospitalised or died – by the time they received their test results. This has had knock-on effects for the contact tracing process as confirmed cases struggled to remember their close contacts over periods of up to three weeks.
“One guy told me to eff off and asked why he should answer our call when we never contacted him when he was sick,” one contact tracer told The Irish Times.
But with the turnaround time for tests now reducing, it is expected contact tracing should be able to operate more efficiently by tracking down contacts more quickly.
The delays in testing also led to many of those engaged to carry out contact tracing being stood down. Of more than 1,400 trained to trace contacts, only 200-300 are being used at present, but this number is expected to increase along with a move to shift working as the operation is widened. Eventually, 4,000 people will work on contract tracing, HSE chief executive Paul Reid has said.
At the start of April, contact tracing was expanded to include contacts of confirmed cases for the 48 hours prior to the onset of their symptoms. This was in recognition of the major role asymptomatic transmission plays in spreading the virus.
Healthcare workers
The tracing of contacts of the 4,000 healthcare workers who have contracted the virus is treated differently from other positive cases. Such cases are handled by clinicians working in occupational health in the HSE rather than the public health division.
This is because of the more complex clinical issues that may be involved, including the application of derogations that allow for healthcare workers to return to work in certain circumstances even where they have been contacts.
The World Health Organisation says "painstaking" contact tracing and rigorous quarantine of close contacts, along with exhaustive case finding, immediate testing and isolation are essential strategies to control Covid-19.
However, it is estimated at least 70-90 per cent of contacts need to be traced quickly in order to stop a new outbreak of the virus.
In late March, the HSE said it was working on a smartphone app to aid contact tracing that would be rolled out within 10 days. The app is still being worked on.
Apps have formed part of the strategy deployed by some Asian countries which have successfully suppressed the virus but take-up of the technology has been lower than optimum.
